4.2BSD/usr/man/man2/link.2

.TH LINK 2 "12 February 1983"
.UC 4
.SH NAME
link \- make a hard link to a file
.SH SYNOPSIS
.nf
.ft B
link(name1, name2)
char *name1, *name2;
.fi
.ft R
.SH DESCRIPTION
A hard link
to
.I name1
is created;
the link has the name
.IR name2 .
.I Name1
must exist.
.PP
With hard links,
both
.I name1
and
.I name2
must be in the same file system.
Unless the caller is the super-user,
.I name1
must not be a directory.
Both the old and the new
.I link
share equal access and rights to
the underlying object.
.SH "RETURN VALUE
Upon successful completion, a value of 0 is returned.  Otherwise,
a value of \-1 is returned and
.I errno
is set to indicate the error.
.SH "ERRORS
.I Link
will fail and no link will be created if one or more of the following
are true:
.TP 15
[EPERM]
Either pathname contains a byte with the high-order bit set.
.TP 15
[ENOENT]
Either pathname was too long.
.TP 15
[ENOTDIR]
A component of either path prefix is not a directory.
.TP 15
[ENOENT]
A component of either path prefix does not exist.
.TP 15
[EACCES]
A component of either path prefix denies search permission.
.TP 15
[ENOENT]
The file named by \fIname1\fP does not exist.
.TP 15
[EEXIST]
The link named by \fIname2\fP does exist.
.TP 15
[EPERM]
The file named by \fIname1\fP is a directory and the effective
user ID is not super-user.
.TP 15
[EXDEV]
The link named by \fIname2\fP and the file named by \fIname1\fP
are on different file systems.
.TP 15
[EACCES]
The requested link requires writing in a directory with a mode
that denies write permission.
.TP 15
[EROFS]
The requested link requires writing in a directory on a read-only file
system.
.TP 15
[EFAULT]
One of the pathnames specified
is outside the process's allocated address space.
.TP 15
[ELOOP]
Too many symbolic links were encountered in translating the pathname.
.SH "SEE ALSO"
symlink(2), unlink(2)